Determination of Molybdenum in Rock and Mineral Samples by Microwave Digestion-Inductively Coupled Plasma-Atomic Emission Spectrometry

Molybdenum in rock and mineral samples were dissolved by HCl-HF-HNO₃ with micro-wave digestion, and measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The experimental conditions for microwave digestion were optimized, for example, select 202.03 nm spectral line for sample analysis, run multi samples simultaneously and reduce the matrix interference by alkali fusion. The damages to the human body were avoided as not using mercury compared with method of polarography. The reliability of the method has been tested by kinds of national standard and results were in agreement with certified value. The recoveries of the method are 96.4%-101.3% with precision of less than 2.0% (RSD, n=8). The detection limit of the method was 0.0005% for molybdenum. The method had been applied to the determination of molybdenum in rock and mineral samples with satisfactory results. The method holds the advantages of low detection limit, good reproducibility, high sensitivity, high efficiency, simple operation and suitable for the routine sample analysis.